Method of manufacturing artificial marble

ABSTRACT

A method for the preparation of an engineered stone slab having coated lumps of composite stone material, the method comprising: scooping a first inorganic particulate material and a polymer material to produce lumps of composite stone material; mixing a second inorganic particulate material with the lumps to produce coated lumps; and adding one or more colorants to the first inorganic particulate material, to the second inorganic particulate material, or to both the first and second inorganic particulate materials.

RELATED APPLICATION

The present application claims benefit under 35 U.S.C. 119(e) of U.S.Provisional Application 60/960,322, filed Sep. 25, 2007, the entiredisclosure of which is incorporated herein by reference.

BACKGROUND

Quartz is the most common oxide on the surface of the earth. Quartz isthe crystalline form of silicon dioxide (SiO₂) and is one of the hardestmaterials in nature. Among many other uses, quartz may be used for theproduction of various stone materials. The quartz containing stonematerials may be used, for example, in the preparation of slabs,surfaces, and the like. Quartz containing stone material may be used forvarious purposes, such as, for example: interior wall cladding,fireplace mantles and surroundings, wainscots and wall bases, bankteller lines, table and desktops, elevator cab walls and floors, floortile and stair treads, food service areas, shower and tub surrounds,toilet compartment partitions, window seats, countertops and backlashes.

As compared to other natural stone compositions, such as granite andmarble, quartz containing stone material may be stronger and moredurable than natural stone compositions. In addition, quartz containingstone material may be cleaner, safer and more consistent than otherstone surfaces. Furthermore, quartz containing stone materials may bemore resistant to: breakage, scratching, stain, heat, chemicals,freeze-thaw damage, and the like.

The production of quartz containing stone material may involve mixinginorganic quartz matrix and organic polymers that may be bound by linkercompounds. The binding between the inorganic quartz matrix and theorganic polymers may influence the resistance of the final compositionof the quartz containing stone material.

SUMMARY

The following embodiments and aspects thereof are described andillustrated in conjunction with systems, tools and methods which aremeant to be exemplary and illustrative, not limiting in scope. Invarious embodiments, one or more of the above-described problems havebeen reduced or eliminated, while other embodiments are directed toother advantages or improvements.

According to some embodiments, lumps (nuggets) of composite material maybe prepared and may further be used for the manufacturing of artificialmarble and artificial marble slabs. The lumps of composite material maybe comprised of various compositions of such materials as inorganicparticulate component (such as silicon, basalt, glass, diamond, rocks,pebbles, shells, a variety of quartz containing materials, and thelike), polymers, binders, mixtures, resins, colorants, dyes, pigments,and the like, or any combination thereof. The lumps of compositematerials may assume any three-dimensional shape, such as for example,squared shape, rounded shape, spiked shape, amorphous and the like, andmay further be prepared at any size. The lumps of composite material mayfurther exhibit any surface type, such as a smooth surface, unevensurface, rigid surface, and the like. The lumps of composite stonematerial may include one or more layers, wherein the layers may havedifferent properties. The lumps of composite material may further beused for the preparation of artificial marble that may exhibit variouspatterns that may be formed by the lumps of composite material.

According to some embodiments, there is provided a method for thepreparation of an engineered stone slab having coated lumps of compositestone material, the method includes scooping a first inorganicparticulate material and a polymer material to produce lumps ofcomposite stone material and mixing a second inorganic particulatematerial with the lumps to produce coated lumps. The scooping, themixing or both may be performed in a mixer having a mixing hook whichcomprises an extension. The extension may include a flat surface, twointerconnected surfaces, a spoon-shaped surface or any combinationthereof. The first inorganic particulate material, the second inorganicparticulate material, or both, may include quartz.

According to further embodiments, the method for the preparation of anengineered stone slab having coated lumps of composite stone materialmay further include adding one or more colorants to the first inorganicparticulate material, the second inorganic particulate material or toboth.

According to other embodiments, the coated lumps may include an innercore having a first property and an outer layer having a secondproperty. The property may include such properties as, color, texture,density, chemical composition, hardness, porousivity or any combinationthereof. The shape of the lumps may substantially round, substantiallycircular, spiked, or any combination thereof.

According to further embodiments, the first inorganic particulatematerial may include particles having a size range of about 0.05 mm toabout 5 mm. The second inorganic particulate material may includeparticles having a size range of about 35 micron to about 50 microns.The polymer may include a binder, hardener, initiator, or anycombination thereof.

According to additional embodiments, the scooping may be performed at avarying mixing speed. The mixing may be performed at a varying mixingspeed.

According to further embodiments, the method for the preparation of anengineered stone slab having coated lumps of composite stone materialmay further include mixing a third inorganic particulate material withthe coated lumps to produce multi-layer coated lumps.

According to some embodiments, there is provided an engineered stoneslab having coated lumps of composite stone material, wherein at least aportion of the coated lumps include an inner core having a firstproperty and an outer layer having a second property. The property mayinclude color, texture, density, chemical composition, hardness,porousivity or any combination thereof. The lumps may include compositestone material. The distribution of the lumps within the slab may beuniform, non-uniform or both. The size of the lumps may be uniform,non-uniform, or both. The shape of the lumps may substantially round,substantially circular, spiked, or any combination thereof.

According to some embodiments, there is provided a method for thepreparation of a composite stone material having over 65% in the form oflumps, the method including mixing inorganic quartz material, addingresin to the inorganic quartz material, and adding ground inorganicquartz material to the mixture of inorganic quartz material and resin,wherein the lumps are adapted to essentially retain the integritythereof. The composite stone material may have over 75% in the form oflumps. The composite stone material may have over 85% in the form oflumps.

According to some embodiments, there is provided a method for thepreparation of a composite stone material, at least a portion of thematerial having a form of lumps, the method including mixing inorganicquartz material, resin, ground inorganic quartz material, wherein themixing is performed by a mixer having mixing blade(s) which include anextended mixing surface such as a spatula or a flat surface, a curvedsurface, two interconnected surfaces, a spoon-shaped surface, or anycombination thereof. The lumps are adapted to essentially retain theintegrity thereof.

According to some embodiments there is provided a method for thepreparation of lumps of composite stone material that may include mixinginorganic quartz material and one or more of the following: colorant,resin, grounded inorganic quartz material, or any combination thereof;and wherein said mixing may be performed at a predetermined speed, suchas in the range of 1-15 m/sec.

According to some embodiments, the inorganic quartz material that may bein the method for the preparation of lumps of composite stone materialmay include sand of various particle sizes, such as in the range ofabout 0.05 mm to 10 mm. The inorganic quartz material may furtherinclude ground sand of a particle size in the range of about 1 micron to65 microns. The particle size may include, for example, the largestdiameter of the particle, the longest dimension of the particle, and thelike. The inorganic quartz material may further include any othernatural and/or artificial material that may contain inorganic quartz,such as, for example, basalt, glass, diamond, rocks, pebbles, shells,silicon, or any combination thereof.

According to some embodiments, the colorant may include any dye,pigment, colorant and any combination thereof. The resin may includepolymer (such as polyester), binder (such as silane), hardener,initiator, and the like, or any combination thereof.

According to some embodiments, the lumps of composite material mayinclude any form, such as, for example, substantially round lumps,substantially circular, spiked, or any combination thereof.

According to further embodiments, the method for preparation of lumps ofcomposite stone material may further include mixing at a predeterminedspeed, such as in the range of, for example, 1 to 15 m/sec. The mixingmay be performed in a mixer or a drum mixer that may further include amodified mixing blade or modified mixing drum, respectively.

According to some embodiments, there is provided an artificial marbleslabs comprising lumps of composite stone materials, wherein at least aportion of the lumps include at least one colored coating layer. Inanother embodiment, at least a portion of the lumps includes two or morecolored coating layers, wherein each layer may be colored by a differentcolorant or a similar colorant at different dosages and/orconcentrations. According to some embodiments, there is provided anartificial marble slab comprising lumps of composite stone materials,wherein at least a portion of the lumps include at least one coloredcoating layer, wherein the resulting slab has a veined effect.

According to some embodiments, there is provided an artificial marbleslab comprising over 65% lumps of composite stone materials. Accordingto some embodiments, there is provided an artificial marble slabcomprising over 75% lumps of composite stone materials. According tosome embodiments, there is provided an artificial marble slab comprisingover 85% lumps of composite stone materials. According to someembodiments, there is provided an artificial marble slab comprising over95% lumps of composite stone materials.

In addition to the exemplary aspects and embodiments described above,further aspects and embodiments will become apparent by reference to thefigures and by study of the following detailed descriptions.

BRIEF DESCRIPTION OF THE FIGURES

FIGS. 1A-F—Schematic illustration of modified mixing blades, accordingto some embodiments;

FIG. 2—Schematic front view illustration of a drum mixer, according tosome embodiments;

FIGS. 3A-B—Schematic illustration of artificial marble, according tosome embodiments; and

FIGS. 3C-J—images of exemplary artificial marble slabs, according tosome embodiments.

DETAILED DESCRIPTION

In the following description, various aspects of the invention will bedescribed. For the purpose of explanation, specific configurations anddetails are set forth in order to provide a thorough understanding ofthe invention. However, it will also be apparent to one skilled in theart that the invention may be practiced without specific details beingpresented herein. Furthermore, well-known features may be omitted orsimplified in order not to obscure the invention.

A composite stone material, such as, for example, artificialmarble/engineered stone/quartz surfaces/composite stone, may be composedof various materials. For example, a composite stone material may becomposed mainly of organic polymer(s) and inorganic particulatecomponent. The inorganic particulate component may include suchcomponents as silicon, basalt, glass, diamond, rocks, pebbles, shells, avariety of quartz containing materials, such as, for example, but notlimited to: crushed quartz, sand, quartz particles, and the like, or anycombination thereof. For example, the inorganic quartz material mayinclude sand of various particle sizes and of different combinations.Linkage between the organic and inorganic compounds may be carried outand/or facilitated by using binder molecules, such as, for example,mono-functional or multifunctional silane molecules, dendrimericmolecules, and the like, that may have the ability to bind the organicand inorganic components of the composite stone. The binders may furtherinclude a mixture of various components, such as initiators, hardeners,catalysators, binding molecules and bridges, or any combination thereof.The manufacturing process of the composite stone material may includeblending of raw material (such as inorganic quartz and organic polymers,unsaturated polymers, and the like, such as polyester) at variousratios. For example, the composite stone material may include about8-95% natural quartz aggregates to about 5-15% polymer resins. Forexample, the composite stone material may include about 93% naturalquartz aggregates and about 7% polymer resins. In addition, any desiredamounts of various additives, may be added to blending of raw materials,at various stages of production. For example, such additives mayinclude, colorants, dyes, pigments, chemical reagents, antimicrobialsubstances, fungicidal agents, and the like, or any combination thereof.As a result of adding various additives to the blending of rawmaterials, the additives may be present in the final composite stoneproduct and may further change various characteristics of the compositestone. Such characteristics may include, for example, physicalproperties, such as: color, texture, display pattern, and the like;chemical properties, such as, for example, chemical resistance, pHproperties, and the like; biological properties, such as, for example,antibacterial properties, and the like; and mechanical properties, suchas, for example, strength, scratch resistance, impact resistance, andthe like. The resulting mixture may later be poured to a support or atemporary support, such as rubber, paper, plastic or any other polymericmaterial, water soluble paper, silicon sheet or the like with or withouta support frame or a shaping frame, a mold such as a rubber tray mold orany other appropriate support. The mixture is poured substantially inthe form of a desired slab (for example, at a size of 306 cm×144 cm withor without wall shaping). The mixture may then be compacted by a specialvacuum and vibration process such as vibrocompaction at high pressure,such as about 100 tons. Then, the compressed mixture may be placed in acuring and/or hardening kiln, for example, at a temperature in the rangeof 80° C. to 115° C. for 30 to 60 minutes until it hardens and assumesnatural stone properties, but with greater performance and higherresistance to stains and impact, as detailed below. After completion ofthe casting process, the slabs may be flattened, gauged, calibrated andpolished to a high and enduring shine or any desired finish to be usedat various settings, such as, for example, interior wall cladding,fireplace mantles and surroundings, wainscots and wall bases, bankteller lines, table and desktops, elevator cab walls and floors, floortile and stair treads, food service areas, shower and tub surrounds,toilet compartment partitions, window seats and countertops.

Composite stone material that may be composed mainly of organicpolymer(s) and inorganic quartz matrix, manufactured as describedhereinabove may possess enhanced properties as compared to naturalstones. For example, the composite stone material may exhibit flexuralstrength in the range of about 485-545 Kg/Cm². For example, thecomposite stone material may exhibit flexural strength of about 515Kg/Cm². Water absorption by weight of the composite stone material maybe at the range of about 0 to 0.04 percent. For example, waterabsorption by weight of the composite stone material may be about 0.02percent. Compressive strength of the composite stone material may be inthe range of 2000-2400 Kg/Cm². For example, compressive strength of thecomposite stone material may be about 2200 Kg/Cm². Freezing compressivestrength (after 25 cycles of freeze-thaw) of the composite stonematerial may be in the range of 1800-2400 Kg/Cm². For example, freezingcompressive strength (after 25 cycles of freeze-thaw) of the compositestone material may be about 2082 Kg/Cm². Absorption of the compositestone material may be in the range of 0 to 0.004 percent. For example,absorption of the composite stone material may be about 0.002 percent.Density of the composite stone material may be in the range of 60 to 80g/cm². Mohs hardness of the composite stone material, as may bedetermined by a scratch test may be in the range of 5-8, on a scale of1-10, wherein 10 is diamond. For example, Mobs hardness of the compositestone material may be about 6.5. Taber abrasion index at 1000 cycles ofthe composite stone material may be in the range of 110-270. Thermalexpansion of the composite stone material may be in the range of 7.5-10(×0.000001 in/in/deg C.). Stain resistance of the composite stonematerial may be in the range of 50-64 (wherein the maximal rating is64). Ball impact resistance of the composite stone material may be inthe range of 80 to 200 cm. Radiant heat resistance of the compositestone material demonstrates no damage. Likewise, boiling water and hightemperature do not demonstrate an effect on the composite stonematerial.

As referred to herein, the terms “lumps”, “lumps of artificial”, “lumpsof composite stone material”, “nuggets”, may interchangeably be used.

As referred to herein, the terms, “composite stone material”,“artificial marble”, “engineered stone” and “quartz surfaces” mayinterchangeably be used.

As referred to herein, the term “colorant” may include dyes, pigments,colorants, and the like, or any combination thereof in any form, such asliquid, paste, fluid, or the like.

As referred to herein, the terms “blade”, “leg”, “hook” in relation to amixing device may interchangeably be used. For example, the terms “mixerblade” and mixer leg” may interchangeably be used.

According to some embodiments, lumps of composite material may beprepared and may further be used for the manufacturing of artificialmarble and artificial marble slabs. The lumps of composite material maybe comprised of various compositions of such materials as inorganicquartz matrixes, polymers, binders, resins, colorants, dyes, pigments,and the like. The lumps of composite materials may assume anythree-dimensional shape, such as, for example, squared shape, roundedshape, spiked shape, diamond-like shape, and the like, and may furtherbe prepared in any size. The lumps of composite material may furtherexhibit any surface type, such as smooth surface, uneven surface, rigidsurface, and the like. The lumps of composite material may further beused for the preparation of artificial marble that may exhibit variouspatterns that may be formed by the lumps of composite material.

According to some embodiments, lumps of composite material may bemanufactured such that they acquire a substantially rounded shape, witha substantially smooth surface and a substantially rigid texture. Upontheir production, the lumps may retain their structure under variousconditions. The lumps of composite material may include such materialsas inorganic quartz matrix, such as sand, of various particle sizesand/or any other material that may contain inorganic quartz; a mixtureof polymers, such as unsaturated polyester diluted with styrene;additional mixtures that may include such materials as silane molecules,binders, hardeners, initiators, inhibitors, pigments, dyes, colorants,and the like. Upon manufacturing of the lumps of composite materials,the lumps may further be used for the preparation of patternedartificial marble articles, such as patterned artificial marble slabs,wherein the lumps formed into the artificial marble articles may createthe exhibited pattern of the artificial marble.

According to some embodiments, the inorganic quartz material may includesand of various particle sizes and indifferent combinations. Forexample, the quartz containing sand may include particles of a size ofabout of 0.05 mm to 10 mm. The quartz containing sand may includeparticles of a size of about of 0.05 mm to 8 mm. The quartz containingsand may include particles of the size of about 0.05 mm to 7 mm. Thequartz containing sand may include particles of the size of about 0.05mm to 6 mm. The quartz containing sand may include particles of the sizeof about 0.05 mm to 5.5 mm. The quartz containing sand may includeparticles of the size of about 0.05 mm to 5 mm. The inorganic quartzmaterial may further include ground/milled sand of various particlesizes and in different combinations. For example, the ground/milledquartz containing sand may include grounded particles of the size ofabout 1 to 65 microns. The ground/milled quartz containing sand mayinclude particles of the size of about 10 to 60 microns. Theground/milled quartz containing sand may include particles of the sizeof about 20 to 55 microns. The ground/milled quartz containing sand mayinclude particles of the size of about 30 to 50 microns. Theground/milled quartz containing sand may include particles of the sizeof about 38 to 45 microns. The inorganic quartz material may furtherinclude such materials as basalt, glass, diamond, rocks, pebbles,shells, silicon, and any other material that may contain inorganicquartz.

According to further embodiments, the lumps of composite material mayfurther include resin that may be mixed with the quartz particles toallow formation of the lumps structures. The resin may be comprised ofpolymers and binders. The polymers may include, for example, suchmaterials as polyester, unsaturated polyester and the like, that may bediluted with, for example styrene. For example, the polymer may becomprised of 65% of unsaturated polyester, diluted with 35% styrene. Thebinders may include a mixture of various components, such as initiators,hardeners, catalysators, binding molecules and bridges, such as Silanbridges, and any other component that is known in the art and may beused for the preparation of composite stone material.

According to some embodiments, the lumps of composite material mayfurther include a colorant that may include various dyes, pigments,colorants or any combination thereof. The colorants may be in the formof liquid, powder, paste, and the like, or any combination thereof. Thecolorants may include any organic or non-organic colorant. The colorantsmay further be diluted with various materials, such as polyester,styrene, butyl benzoate, methoxy propyl acetate, and the like. Thecolorants may be added at various stages during the manufacturingprocess of the lumps of composite material. The colorants may be addedin various concentrations and various amounts during various stages ofthe manufacturing process. Furthermore, one or more colorants and/or acombination of colorants may be added during various stages of themanufacturing procedures of the lumps of composite materials.

According to some embodiments, the preparation of lumps of compositematerial may be performed in one or more mixing devices. The mixingdevices may include any known mixing device, such as, for example, amixer, a vertical axis mixer, a drum mixer, palletizer, and the like, orany combination thereof. In addition, the modifications to the mixingdevice may also be performed, wherein said modifications may aid in thepreparation process of the lumps of composite material.

According to some exemplary embodiments, the preparation of lumps ofcomposite material may be performed using a mixer. The mixer may includeany kind of mixer, such as a vertical axis mixer. For example, the mixermay include a vertical mixer as described in publication no. WO2006/084792, incorporated herein by reference. The mixer may have one ormore mixing legs that may be attached to a common arm (that may bealigned with the revolving axis) and may thus revolve around a commonaxis. The mixing legs may be placed at varying distances from each otherand may be located at any angle relative to the common axis. The mixerlegs may revolve independently from each other, the mixer legs mayrevolve in synchronization with each other, or any combination thereof.The mixer may further include a container (such as a mixing bowl), intowhich various components of the lumps' composition may be added at anappropriate, predetermined order; at an appropriate time schedule; andat appropriate mixing conditions. Mixing conditions may include suchconditions as mixing speed, mixing temperature and mixing blades thatmay be used. For example, mixing speed may be measured in units ofrotational speed (rounds per minute (rpm)) and/or in units of peripheralspeed (m/sec). For example, mixing speed may vary between differentstages of the manufacturing process of the lumps of composite materialand may be in the range of, for example, 1 to 15 m/sec. The mixing speedmay include mixing at low speed, such as, for example in the range of,about 1 to 2 m/sec. For example, mixing temperature may be measured asthe environment temperature or the container temperature at which themixing procedure is being performed. For example, the mixing temperaturemay be in the range of 4 to 40 degrees Celsius. For example, the mixingtemperature may be performed at room temperature, such as, for example,at the temperature of about 25 degrees Celsius. In addition, one or moreof the mixing blades (mixing legs) used in the mixer may be adapted tobe used for the formation of the lumps of the composite material.According to some embodiments, one or more of the mixer blades (legs)may be modified and adapted such that, at the end of the blades, at theregion that contacts the materials to be mixed, an extended surface areamay form. The extended surface area may be achieved, for example, byattaching an extension of various forms to the end of the mixing blade.The extension may assume various forms, such as, but not limited to: aflat, quadrangular plate; a plate that may be comprised of at least twoflat surfaces; a spoon shaped plate, curved plate, and the like. Theextension may further be situated at various angles as compared to theperpendicular axis of the mixer blade. Reference is now made to FIG. 1,which schematically illustrates modified mixing blades, according tosome embodiments. As illustrated in FIG. 1A, which illustrates a frontview of a modified mixing blade, according to some embodiments, anextension (such as extension 4 in FIG. 1A) may be attached to the mixingend (such as end 6) of the mixing blade (such as mixing blade 8).Extension 4 may have a shape of a flat quadrangular plate, wherein themixing blade is attached at any point on the upper rib (10) of thecircumference of the plate. The extension plate may be connected atvarious angles relative to the perpendicular axis (such as axis y inFIG. 1A) of the mixing blade. Reference is now made to FIGS. 1B and 1C,which illustrate a side view of a mixing blade with an extension plate.As shown in FIG. 1B, extension plate 4 may be attached to mixing blade 8perpendicularly (at 0 degrees) to the perpendicular axis (y) of themixing blade (12). As shown in FIG. 1C, extension plate 4 may beattached to mixing blade 8 at an angle (α), which may be the anglebetween the upper rib (10) of the circumference of extension plate (4)and the perpendicular axis (y) of the mixing blade (12). Angle α may beany angle in the range of 0-180 degrees. According to other embodiments,extension to the mixing blade may include a plate that may have at leasttwo planar flat quadrangle surfaces that may be positioned at any anglerelative to each other. As illustrated in exemplary manner in FIG. 1D,which illustrates a side view of a mixer blade with an extension,according to some embodiments, the surfaces, such as upper surface 22and lower surface 24, may be positioned at an angle β relative to eachother, to form extension 20. Angle β may be any angle in the range of 0to 90 degrees. Extension 20 may be situated at any angle (γ) relative tothe perpendicular axis (y2) of the mixing blade (26), wherein angle γmay be any angle in the range of 0-180 degrees and may be the anglebetween the upper rib (not shown) of the circumference of the uppersurface (22) of extension plate (20) and the perpendicular axis (y2) ofthe mixing blade (26). Angle γ may be any angle in the range of 0-180degrees. According to other embodiments, the extension of the mixingblade may include any concaved shaped form, such as, for example, aspoon shaped form. As shown in FIG. 1E by way of example, of a side viewof a mixing extension, according to some embodiments, extension 40 mayhave a concaved, spoon-like shape that may be attached to the mixingblade (42). Extension 40 may be attached to mixing blade 42 at an angle(δ), which may be the angle formed between the central perpendicularaxis (y3) of extension, such as extension 40 and the perpendicular axis(y3) of the mixing blade (42). Angle δ may be any angle in the range of0-180 degrees. As illustrated in FIG. 1F, which illustrates a front viewof a modified mixing blade, according to some embodiments, an extension(such as extension 54 in FIG. 1F) may be attached to the mixing end(such as end 56) of the mixing blade (such as mixing blade 58).Extension 54 may have a curved shape, and the mixing blade may beattached at any point on the upper rib (50) of the circumference of theextension plate. The extension plate may be connected at various anglesrelative to the perpendicular axis (such as axis y in FIG. 1F) of themixing blade. Attachment between the mixing blade and the extension maybe performed by various methods such as, adhering, welding, mechanicalfitting, by use of bolts and nuts, and the like. The attachment betweenthe mixing blade and the extension may be reversible or permanent.Attachment between the mixing blade and the extension may be performedsuch that the extension may form as an integral part of the mixing bladeand/or as an integral extension of the mixing blade. Attachment betweenthe mixing blade and the extension may be reversible and may allowchanging the extension that may connect to the mixing blade.

Use of mixing blade extension such as the extensions exemplifiedhereinabove may aid in the formation of a desired form of the lumps ofcomposite material. For example, the mixing process with the variousextensions may result in a scooping action that may mix while shapingthe form of the resulting lumps. For example, as a result of thescooping actions of the modified mixing blades, substantially roundedball-like shaped lumps may be formed. Moreover, the scooping action mayyield increasingly larger lumps, wherein the diameter of the roundedball shaped lumps may be increased as a result of the continuous mixingaction. The effect of the increasingly larger lumps may also be namedherein as the “snow ball effect”, as it may resemble in concept theformation of a snow ball, wherein the more turns the ball revolves, themore material (“snow”) is collected on the face of the ball, and as aresult the diameter of the ball is increased.

According to additional embodiments, the mixer may include a drum mixer.A drum mixer may include a revolving drum that may be used for mixing ofmaterials contained within the interior of the drum. As a result of therevolving movement of the drum along a central axis, the materialsinside the drum may mix. In addition, the drum mixer may include amodified drum, wherein the interior walls of the drum may include ridgesand/or perforations that may function as mixing blades that may increasethe mixing efficiency and may further aid in a desired formation oflumps of composite materials. The cavity of the drum may include mixingblades that may be situated in any location within the drum cavity. Themixing blades may revolve independently of the mixing drum and may thusincrease efficiency of the mixing and further aid in the formation oflumps of composite material. Reference is now made to FIG. 2, whichschematically illustrates a front view of a drum mixer, according tosome embodiments. As illustrated in FIG. 2, the drum mixer may include amixing drum, such as drum 80 that may revolve clockwise around axis 82.A drum, such as drum 80, may include inner cavity, such as cavity 84into which various materials to be mixed may be added. The interiorwalls of a drum, such as drum 80, may include perforations and ridges,such as ridges 86A-F, that may be situated at various distances alongthe interior walls of drum 80. Ridges, such as 86A-F may include flatelongated ridges that may protrude from the interior walls of the drumtowards the cavity of the drum. Ridges on the interior walls of the drummay include any number of ridges that may be situated at varyingdistances from each other along the interior walls of the drum. Theridges on the interior walls of drum 80 may form as an integral part ofthe interior walls of the drum, or may be attached by various methods tothe interior walls of the drum. According to some embodiments, theridges along the interior walls of the mixing drum may aid in theformation of a desired form of the lumps of composite material that maybe mixed in the drum cavity. The revolving motion of the drum, incombination with the ridges in the interior walls of the mixing drum,may result in a scooping action that may mix while shaping the form ofthe resulting lumps. For example, as a result of the scooping actions ofthe revolving drum with the ridges on its interior walls, substantiallyrounded ball-like shaped lumps may be formed. Moreover, the scoopingaction may yield increasingly larger lumps, wherein the diameter of therounded ball shaped lumps may be increased as a result of the continuousmixing action, in the snowball effect.

According to some embodiments, there is provided a method ofmanufacturing lumps of composite materials. The method may include, forexample, mixing various quartz containing compositions, such as sand, ofvarious particle sizes; addition of various colorants in variousconcentrations and amounts; additions of various resins, such as resinsdescribed hereinabove; at any predetermined order of addition and at anytime predetermined time intervals between the various additions. Themixing may be performed in a mixer that may include modified mixingblades, in a drum mixer that may include a modified drum interior or anadditional mixing blade(s), in a palletizer and any combination thereof.The method may further result in the production of lumps, wherein atleast 60% of the mixture is converted to lumps at the termination of theprocess and wherein the lumps thus produced retain a stable structure.According to some embodiments, the method may further result in theproduction of lumps, wherein at least 85% of the mixture is converted tolumps at the termination of the process and wherein the lumps thusproduced retain a stable structure. The lumps of composite materialsthus manufactured may acquire the shape of, for example, substantiallyround balls, with a substantially smooth surface. The manufactured lumpsof composite material may further be used for the preparation ofartificial marble slabs. To this aim, the lumps of composite materialmay be poured into a mold in the form of a slab, which may then becompacted by a special vacuum and vibration process, at a pressure ofabout 100 tons. Then the slabs may be placed in a curing kiln, untilthey harden. The hardened slabs formed in this manner may exhibit adisplay pattern comprised of the arrangement of the lumps of thecomposite material within the compacted artificial marble slabs.

According to some embodiments, the properties of the lumps of compositematerial, such as shape, size, color, texture, strength, and the likemay be determined by various factors. The factors may include chemicalfactors (such as mixture compositions), physical factors (such as sizeand form of particles in the mixture), mechanical factors (speed ofmixing, type of mixer and mixing blade used), and the like. For example,the factors may include such factors as: the order at which the variousconstituents of the lumps are added into the mixture; the time intervalsat which the various constituents are added into the mixture; theproperties and appearance of the various constituents that are addedinto the mixture (size of particles, powder, liquid, and the like); thetime intervals between the addition of the various constituents of themixture (such as colorants, resins, and the like); the speed of mixingafter and during addition of the various mixture constituents; the typeand size of extension of the mixing blade; the size of the resultinglumps, the distribution of the resulting lumps in the slab, and thelike.

According to further embodiments, the process of the preparation oflumps of composite material may include a continuous process and/orbatch process. In a batch process, a mixture of various materials ismixed according to the manufacturing process, and the lumps that formmay be collected at the end of the manufacturing process, which mayterminate when the materials are all used/converted to lumps. In acontinuous process, a continuous supply of materials is added to themixture, and lumps are continuously formed and collected, throughout themanufacturing process.

According to some exemplary embodiments, the method for manufacturinglumps of composite material may include such steps as: unloading quartzparticles, such as in the form of sand in the size of about 0.01 mm to 8mm into a mixer bowl. For example, the size of the quartz particles maybe in the range of, for example 0.065 mm to 2 mm. The mixer may beequipped with modified mixing blades that may include extensions, suchas in the form of spoons. The mixer may mix at a speed in the range of,for example 6 to 14 rpm. Into the mixture, a colorant may be added. Thecolorant may be in the form of a powder or a liquid. The quartzparticles and the colorant may be mixed at a speed of 1 to 10 rpm forabout 1 to 10 seconds, after which the speed may be increased to, forexample, the range of 12 to 24 rpm for additional 30 to 90 seconds. Intothe mixture of quartz particles and colorant, a resin may be added.Addition of the resin may be performed while the mixer is mixing at aspeed of, for example, 4 to 12 rpm. Upon addition of the resin, it maybe mixed with the mixture of quartz particles and colorant at a speedof, for example, 1 to 10 rpm, and then the speed may be increased to aspeed of, for example, 8 to 24 rpm. Next, additional quartz particlesmay be added to the mixture, while the mixture is mixing at the speed ofabout 2-12 rpm. The quartz particles added may be in the form ofground/milled quartz containing sand that may include particles of thesize of about 1 to 60 microns. For example, the added ground/milled sandmay include particles in the size of about 1 to 38 micron. For example,the added ground/milled sand may include particles in the size of about38 to 45 micron. Upon addition of the ground sand particles to themixture, the mixer may mix at a speed in the range of 2 to 12 rpm for 1to 20 seconds, after which the mixer speed may be increased to a speedin the range of 12 to 26 rpm for a length of time of 20 to 80 seconds.Next, additional resin composition may be added to the mixture, whilethe mixer is mixing at a speed in the range of about 2 to 14 rpm. Next,one or more additional colorants may be added, together or sequentially,and mixed under conditions as above. The next mixing step of theresulting mixture may include mixing at a speed in the range of 8 to 22rpm for 10 to 80 seconds. The final mixing step of the resulting mixturemay include mixing at a speed of 2 to 14 rpm for about 500 to 1500seconds. The final mixing step may be performed in the presence ofcolorant, which may result in the formation of lumps that may include acolor coating at their outer surface. Furthermore, after the finalmixing step, a colorant may be added to the mixture, and the mixer maymix for additional 10-120 seconds, at a speed of 2-12 rpm. This step mayfurther result in the formation of lumps that may include a colorcoating at their outer surface.

According to some embodiments, the method for manufacturing lumps ofcomposite material may result in the formation of substantially smooth,round, shaped lumps that may exhibit various colors and various sizes.Timing of addition of the colorant(s) to the mixture of the lumps ofcomposite materials, amount of colorant(s) added to the mixture, and/ortype of colorant(s) added to the mixture may determine the finalappearance of the resulting lumps. For example, the lumps may exhibitmore than one color that may be distributed within and/or on the surfaceof the lumps. For example, the color(s) may be distributed evenly withinthe lumps; the colors may be distributed evenly on the surface of thelumps; the colors may be distributed unevenly within the lumps; thecolors may be distributed unevenly on the surface of the lumps, and/orany combination thereof. According to some exemplary embodiments, theinterior layers (core) of the lumps may include one or more colorants,and the exterior layer (surface) of the lumps may be coated withadditional colorant(s).

According to some embodiments, the lumps of composite materialmanufactured as detailed hereinabove may be used for the preparation ofpatterned artificial marble and patterned artificial marble slabs. Forexample, lumps of a desired form (for example, rounded lumps); and of adesired size (for example, a diameter of 0.01-10 cm, a diameter in therange of 0.5-2 cm, and the like); and of a desired texture (for example,smooth); of a desired color or combination of colors; and of a desiredcolor distribution (for example, within the lumps, at the externalsurface of the lumps, and the like) may be used for the preparation ofartificial marble slabs. The lumps may be mixed with one or moreadditional materials such as: organic polymer(s) (like resins);inorganic quartz matrix; linkers (such as silane molecules); additionalcolorants (such as dye, pigments, and the like); chemical reagents;antimicrobial reagents; and the like that may be used in the creation ofthe artificial marble slabs. The resulting mixture may be poured into amold in the form of a slab (for example, at a size of 306 cm×144 cm).The slab may then be compacted by a special vacuum and vibration processat a pressure of about 100 tons. Then the slabs may be placed in acuring kiln, for example, at 80° C. to 115° C. for 30 to 45 minutesuntil they harden and assume natural stone properties, with a patternthat may be created by the lumps of composite material that were usedfor the preparation of the artificial marble.

Reference is now made to FIGS. 3A-B, which illustrate schematic drawingsof artificial marble slabs, manufactured by using lumps of compositematerial, according to some embodiments. As mentioned hereinabove, thecharacteristics of the lumps used for the preparation of the artificialmarble slabs, such form of the lumps, size of the lumps, texture of thelumps, color of the lumps, color distribution of the lumps, and thelike, may determine the pattern of the artificial marble slabs. Forexample, FIG. 3A schematically illustrates an artificial marble slabprepared by use of lumps and additional materials, as detailedhereinabove. As shown in FIG. 3A, an artificial marble slab, such asslab 100, may exhibit a pattern that may be created by lumps, such aslumps 102A-F. Lumps, such as 102A-F may be small diameter round lumps,and the space between the lumps (matrix, 104) may include additionalmaterials, such as organic polymer inorganic quartz matrix; linkers suchas silane molecules, and the like that may be used as fillers.Additional example is illustrated in FIG. 3B, which schematicallyillustrates an artificial marble slab prepared by use of lumps andadditional materials, as detailed hereinabove. As shown in FIG. 3B, anartificial marble slab, such as slab 110, may exhibit a pattern that maybe created by lumps, such as lumps 112A-F. Lumps, such as 112A-F, may belarge diameter round lumps. The small space that may form between thelumps (matrix, 114) may include additional materials, such as organicpolymer inorganic quartz matrix; linkers such as silane molecules, andthe like.

Reference is now made to FIGS. 3C-J, which show exemplary pictures ofartificial marble slabs, prepared by use of lumps and additionalmaterials, as detailed hereinabove. As shown in FIG. 3C, an artificialmarble slab, such as slab 120, may exhibit a pattern that may be createdby lumps, such as, for example, lumps 122A-D. Lumps, such as 112A-D maybe substantially round (circular) lumps that may comprise essentiallymost of the area of the artificial marble slab. The lumps may includeone or more colorants, wherein the inner layer (core) of the lump is ofa different color than the outer layer (surface) of the lump. As shownin FIG. 3D, an artificial marble slab, such as slab 130, may exhibit apattern that may be created by lumps, such as lumps 132A-D. Lumps, suchas, for example, 132A-D may be substantially circular lumps that maycomprise essentially most of the area of the artificial marble slab. Thelumps may include one or more colorants, dispersed in various layers ofthe lump. As shown in FIG. 3E, an artificial marble slab, such as slab140, may exhibit a pattern that may be created by lumps, such as, forexample, lumps 142A-D. Lumps, such as 142A-D may be substantiallycircular lumps that may comprise essentially most of the area of theartificial marble slab. The lumps may include one or more colorants invarious layers of the lump composition. For example, a lump, such aslump 142E may include a first colorant (144A) and second colorant (144B)at internal layers (core); and an additional colorant (144C) coating theouter layer (boundaries/surface) of the lump. As shown in FIG. 3F, anartificial marble slab, such as 150, may exhibit a pattern that may becreated by lumps, such as, for example, lumps 152A-D. Lumps, such as152A-D, may be substantially circular lumps that may compriseessentially most of the area of the artificial marble slab. The lumpsmay include one or more colorants, dispersed in various layers of thelump. As shown in FIG. 3G, an artificial marble slab, such as slab 160,may exhibit a pattern that may be created by lumps, such as lumps162A-D. Lumps, such as 162A-D, may be substantially round lumps that maycomprise at least part the area of the artificial marble slab. The spacebetween the lumps, shown as bright background is the matrix (164) of theslab. The lumps may include one or more colorants, dispersed in variouslayers of the lump. As shown in FIG. 3H, an artificial marble slab, suchas slab 170, may exhibit a pattern that may be created by lumps, suchas, for example, lumps 172A-D. Lumps, such as 172A-D may besubstantially amorphous lumps that may comprise at least part of thearea of the artificial marble slab. The space between the lumps, shownas dark background is the matrix (174) of the slab. The lumps mayinclude one or more colorants at various layers of the lump composition.For example, a lump, such as lump 172E, may include a first colorant(174A) at an internal layer (core) and additional colorant (174B) at anouter layer of the lump. As shown in FIG. 3I, an artificial marble slab,such as slab 180, may exhibit a pattern that may be created by lumps,such as, for example, lumps 182A-D. Lumps, such as 182A-D may besubstantially circular-spiked lumps that may comprise at least part ofthe area of the artificial marble slab. The space between the lumps,shown as bright background is the matrix (184) of the slab. As shown inFIG. 3J, an artificial marble slab, such as 190, may exhibit a patternthat may be created by lumps, such as, for example, lumps 192A-D. Lumps,such as 192A-D may be substantially circular (round) lumps that maycomprise essentially most of the area of the artificial marble slab. Thelumps may further include one or more colorants that may be dispersed invarious layers of the lump.

While a number of exemplary aspects and embodiments have been discussedabove, those of skill in the art will recognize certain modifications,permutations, additions and sub-combinations thereof. It is, therefore,intended that the following appended claims and claims hereafterintroduced be interpreted to include all such modifications,permutations, additions and sub-combinations as are within their truespirit and scope.

1. A method for the preparation of an engineered stone slab having coated lumps of composite stone material, the method comprising: scooping a first inorganic particulate material and a polymer material to produce lumps of composite stone material; mixing a second inorganic particulate material with the lumps to produce coated lumps; and adding one or more colorants to the first inorganic particulate material, to the second inorganic particulate material, or to both the first and second inorganic particulate materials.
 2. The method of claim 1, wherein said scooping, the mixing or both are performed in a mixer having a mixing hook which comprises an extension.
 3. The method of claim 2 wherein said extension comprises a flat surface, two interconnected surfaces, a spoon-shaped surface or any combination thereof.
 4. The method of claim 1, wherein the first inorganic particulate material, the second inorganic particulate material, or both, comprise quartz.
 5. The method of claim 1, wherein the coated lumps comprise an inner core having a first property and an outer layer having a second property.
 6. The method of claim 5, wherein the property comprises color, texture, density, chemical composition, hardness, porousivity or any combination thereof.
 7. The method of claim 1, wherein the first inorganic particulate material comprises particles having a size range of about 0.05 mm to about 5 mm.
 8. The method of claim 1, wherein the second inorganic particulate material comprises particles having a size range of about 35 micron to about 50 microns.
 9. The method of claim 1, wherein polymer comprises a binder, hardener, initiator, or any combination thereof.
 10. The method of claim 1, wherein the shape of the lumps is substantially round, substantially circular, spiked, or any combination thereof.
 11. The method of claim 1, wherein the scooping is performed at a varying mixing speed.
 12. The method of claim 1, wherein the mixing is performed at a varying mixing speed.
 13. The method of claim 1, further comprising mixing a third inorganic particulate material with the coated lumps to produce multi-layer coated lumps. 